TL;DR Caffeine has several positive effects on your brain, especially in terms of concentration and mental performance. Experts say that the optimal way to maximize these effects is to have caffeine every 48 hours.
What if I tell you that aside from perking you up, caffeine can also help you concentrate and become more productive?
If, during mind-numbing, brain-wracking moments, you want to feel like Popeye going for a whole can of spinach, just reach out for the coffee-maker and you’re likely to feel the same! (For the best java experience, know when’s the best time to drink your coffee here.)
Caffeine can also help you absorb information and remember it more efficiently.
Yep! Our favorite stimulant can boost mental performance in more ways than one. Have a cuppa and you’ll find yourself retaining more information from classes and business meetings, kill it in planning and problem-solving, and finish those day-to-day tasks efficiently.
Without further ado, here are 8 ways caffeine can help us take a step closer to becoming Einstein-genius:
1. Caffeine makes you more alert, attentive and laser-focused.
In fact, according to the European Food Safety Authority (EFSA), there’s a direct causal relationship between 75mg of caffeine, which is equivalent to a tall cup of coffee, and a higher level of attention and alertness. 
2. Caffeine can help you feel more awake.
If you find yourself lacking focus and alertness because you stayed until the wee hours last night, fret not. You can turn to caffeine for an instant rescue.
According to various studies, caffeine can help pull you through extremely sleepy but highly-important-to-stay-awake moments, such as:
Cognitive function refers to our body’s ability to absorb and retain information and knowledge. Specifically, it involves learning, memory, reasoning, attentiveness, and language.
According to a study done by researchers from the Department of Psychiatry and Clinical Psychobiology at the University of Barcelona, caffeinated beverages mixed with sugar (glucose) can “improve cognitive performance in terms of sustained attention and working memory.” 
Studies also show that caffeine helps you learn more efficiently by up to 10%. 
4. Caffeine can help keep your brain young.
Caffeine is also found to improve cognitive function in the long-haul and strengthens it upon aging. It slows mental decline associated with age. 
5. Caffeine helps you remember.
Johns Hopkins researchers have found caffeine to be an effective memory-enhancer. Specifically, a study conducted in 2014 concluded that caffeine can help you remember things for up to 24 hours, even enhancing long-term memory. 
According to Michael Yassa, an assistant professor of psychological and brain sciences at Johns Hopkins and the team lead of said study,
"We've always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans… We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours.”
6. Caffeine helps you plan better.
A 2005 study conducted at the Medical University at Innsbruck, Austria shows that caffeine promotes higher activity in parts of the brain involved in planning, attention, monitoring, and concentration. 
7. Caffeine leads to higher concentration among children, specifically those suffering from ADHD.
It may be hard to imagine how caffeine, a stimulant, can be used as a potential treatment to ADHD. But studies have shown that caffeine can help with ADHD, as it:
Increases dopamine levels, the hormone linked to pleasure, attention and movement
8. Caffeine helps athletes concentrate and perform optimally.
A 2008 research conducted by B. Sökmen, L.E.Armstrong and their team found that caffeine boosts cognitive function among athletes, especially when taken before a training exercise. It has been reported to improve concentration especially when the athlete lacks a good night sleep the prior night. 
With all these brain-wracking benefits of caffeine, one question remains:
How do we make the most of our caffeine fix?
The answer is plain and simple according to this article from QT: For an optimal mental performance, have a cup every 48 hours.
The hack is simple: if you are an average adult, a cup of coffee every 48 hours will do the trick. (Disclosure: I’ve been doing this for more than two years.) A typical cup of coffee contains 80mg of caffeine, which as a non-addict should be enough to give you the mental boost. You can have a double espresso shot too, if you like. The half-life law will ensure that most of it is out of your system in 48 hours. But break the 48-hour-gap law at your own risk.
However, if 48 hours is too much of a wait for you, don’t worry. You can still have your java multiple times a day without getting over-caffeinated. Just keep in mind how much caffeine you should have in a day.
To find out more about how exactly coffee works on your brain, watch this video:
Erectile dysfunction. In combination, those are two of the ugliest words known to man. But can caffeine help you get it up?
Science hasn't found the definitive answer to this question, but one study concluded that fewer men who consume caffeine have problems performing. The study said:
Caffeine intake reduced the odds of prevalent ED, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive, but not among diabetic men. Yet, these associations are warranted to be investigated in prospective studies